tempfileservice.java

一个很好的LIBSVM的JAVA源码。对于要研究和改进SVM算法的学者。可以参考。来自数据挖掘工具YALE工具包。

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2001-2004
 *      Simon Fischer, Ralf Klinkenberg, Ingo Mierswa, 
 *          Katharina Morik, Oliver Ritthoff
 *      Artificial Intelligence Unit
 *      Computer Science Department
 *      University of Dortmund
 *      44221 Dortmund,  Germany
 *  email: [e-mail]
 *  web:   http://yale.cs.uni-dortmund.de/
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as 
 *  published by the Free Software Foundation; either version 2 of the
 *  License, or (at your option) any later version. 
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA.
 */
package edu.udo.cs.yale.tools;

import edu.udo.cs.yale.Yale;
import edu.udo.cs.yale.Experiment;
import edu.udo.cs.yale.operator.OperatorException;

import java.io.*;

import java.util.List;
import java.util.LinkedList;
import java.util.ListIterator;

/** This class manages temporary files like model files, files with 
 *  predicted labels, and so on.
 *     The methods of this class can handle given strings that shall
 *  be part of the name of the temporary files and automatically 
 *  increments a counter that is also part of these file names. 
 *     Methods for using base files or renaming are also included.
 *  The user can choose, whether all temporary files are to be kept
 *  or to be deleted as soon as they are no longer needed or as soon
 *  as the YALE has completed the whole experiment.
 *
 *  Parameters read from the experiment configuration file:
 *  <ul>
 *    <li><code>temp_dir</code>: Name of the directory for the
 *        temporary files.</li>
 *    <li><code>keep_temp_files</code>: Either <code>none</code>
 *        or <code>all</code> indicating whether no temporary
 *        or all temporary files should be kept when they are
 *        no longer needed by YALE.</li>
 *  </ul>
 *  <br>
 *
 *  @author Ingo Mierswa
 *  @version $Id: TempFileService.java,v 2.12 2004/08/27 11:57:45 ingomierswa Exp $
 */
public class TempFileService {

    public static final String[] DELETE_TEMP_FILES = { "no", "directly", "on_exit" };
    public static final int NO       = 0;
    public static final int DIRECTLY = 1;  // ?? comments on semantics and procedure ??
    public static final int ON_EXIT  = 2;

    /** Indicates wether or not deleteOnExit() should be invoked on all created temporary files. 
     *  One out of NO, DIRECTLY, and ON_EXIT. */
    private static int deleteTempFiles;

    /** Prefix of all files. The value is &quot;_yale_&quot;. */
    private static final String TMP_PREFIX="_yale_";

    /** Directory of all temp files. */
    private static File tmpDir;

    /** Directory of all temp files. */
    private static String tmpDirString;


    /** Initializes the temp file service. */
    public static void init(Experiment experiment) throws OperatorException {
	TempFileService.deleteTempFiles = experiment.getRootOperator().getParameterAsInt("delete_temp_files");
	String tempDirName = experiment.getRootOperator().getParameterAsString("temp_dir");
        LogService.logMessage("TempFileService: delete_temp_files = "+
                              DELETE_TEMP_FILES[TempFileService.deleteTempFiles],
                              LogService.MINIMUM);

	if (tempDirName == null) {
	    File experimentFile = experiment.getExperimentFile();
	    if (experimentFile == null) {
		tempDirName = "unnamed.tmp";
	    } else {
		tempDirName = experimentFile.getName()+".tmp";
	    }
	}

	TempFileService.tmpDir = experiment.resolveFileName(tempDirName);

	if (!tmpDir.exists()) {
	    LogService.logMessage("Creating temp directory "+tmpDir, LogService.INIT);
	    if (!Tools.mkdir(tmpDir.getAbsoluteFile())) {
		throw new OperatorException("Cannot create temp directory "+tmpDir);
	    } else {
		if (deleteTempFiles > NO) 
		    tmpDir.deleteOnExit();
	    }
	}
    }


    /** Creates a new temp file with a name build of prefix and the current file index. */
    public static File createTempFile() {
	try {
	    File file = File.createTempFile(TMP_PREFIX, null, tmpDir);
	    return file;
	} catch (IOException e) {
	    throw new RuntimeException(e.toString() + ": Cannot create temp file.");
	}
    }


    /** Like <code>createTempFile</code>, additionally the given name is part of the file name. */
    public static File createTempFile(String name) {
	try {
	    File file = File.createTempFile(TMP_PREFIX+name, null, tmpDir);
	    return file;
	} catch (IOException e) {
	    throw new RuntimeException(e.toString() + ": Cannot create temp file.");
	}
    }


    /** Gets a file and renames it to prefix + current file index. */
    public static File createTempFile(File oldfile) {
	return createTempFile("", oldfile);
    }


    /** Like <code>createTempFile(File)</code>, additionally the given name is part of the file name. 
     */
    public static File createTempFile(String name, File oldfile) {
	try {
	    File newfile = File.createTempFile(TMP_PREFIX+name, null, tmpDir);
	    if (!oldfile.exists()) {
		throw new RuntimeException("TempFileService: Cannot rename file '"+oldfile.getPath()+
					   ". File does not exist.");
	    }	
	    // neccessary for Windows OS
	    if (newfile.exists()) newfile.delete();
	    
	    if (oldfile.renameTo(newfile)) {
		LogService.logMessage("TempFileService: Renamed file '" + oldfile.getPath() + 
				      "' to '"+newfile.getPath()+"'.", 
				      LogService.MINIMUM);
	    } else {
		throw new RuntimeException("TempFileService: Cannot rename '"+oldfile.getPath()+
					   "' to '"+newfile.getPath()+"'! Original file exists, "+
					   "but cannot be renamed.");
	    }
	    if (deleteTempFiles > NO) newfile.deleteOnExit();
	    return newfile;
	} catch (IOException e) {
	    throw new RuntimeException(e.toString() + ": Cannot create temp file.");
	}
    }


    /** Fills the given file array with files of a created filestem (which will be returned), 
     *  and each of the extensions. */
    public static String createTempFiles(String name, String[] extensions, File[] files) {
	try {
	    File tempFile = File.createTempFile(TMP_PREFIX + name, "", tmpDir);
	    for (int i = 0; i < files.length; i++) {
		files[i] = new File(tempFile.getAbsolutePath() + extensions[i]);
		if (deleteTempFiles > NO) files[i].deleteOnExit();
	    }
	    return tempFile.getAbsolutePath();
	} catch (IOException e) {
	    throw new RuntimeException(e.toString() + ": Cannot create temp file.");
	}
    }

    /** Deletes the file if delete_temp_files is set to DIRECTLY. */
    public static void deleteTempFile(File file) {
	switch (deleteTempFiles) {
	case DIRECTLY: 
	    if (file.exists()) {
		LogService.logMessage("Deleting temporary file '"+file.getName()+"' ("+file.length()+" bytes)", 
				      LogService.MINIMUM);
		file.delete(); 
	    }
	    return;
	case ON_EXIT: 
	    file.deleteOnExit(); 
	    return;
	}
    }

    /** Returns the temp dir. */
    public static File getTempDir() {
	return tmpDir;
    }
}